Programmable Thin Film Deposition via Inkjet Dispensing
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Solution Overview
Problem
Current thin film deposition techniques lack the ability to form intentionally non-uniform films without significant material wastage and are often expensive due to the need for vacuum processing.
Innovation Solution
The Programmable Inkjetting of Thin-films (PAINT) process uses an array of inkjet nozzles to dispense precursor liquid material on a substrate, allowing for the formation of non-uniform films by optimizing drop volume and location, and utilizing a flexible superstrate to create a contiguous film that is then cured and separated, enabling precise control over film thickness profiles with near-zero material wastage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deposition techniques (spin-coating, CVD, PVD) are used to deposit thin films, then uniform film thickness is achieved, but the ability to form intentionally non-uniform films is lost and significant material wastage occurs
Solution Approach 1:
The deposition process is segmented into discrete droplet placements rather than continuous coating. Individual droplets are deposited at specific locations and allowed to spread and merge, enabling precise control over local film thickness while maintaining overall uniformity when needed.
Solution Approach 2:
Different regions of the substrate receive different numbers and volumes of droplets, creating locally optimized film thickness. The system can deposit varying amounts of material at different locations to achieve intentionally non-uniform profiles or highly uniform films depending on the application requirements.
2Reliability
If vacuum processes are used for deposition, then film deposition is achieved, but processing cost increases due to the need for vacuum chambers
Solution Approach 1:
The vacuum mechanical system is replaced with a atmospheric pressure liquid dispensing system. Instead of using vacuum chambers and pumps, the invention uses inkjet-style droplet dispensing at atmospheric pressure, dramatically reducing equipment complexity and cost while maintaining film deposition quality.
Solution Approach 2:
The process transitions from gas-phase vacuum deposition to liquid-phase atmospheric deposition. By changing the material phase from vapor to liquid and the operating pressure from vacuum to atmospheric, the system achieves comparable film quality without expensive vacuum infrastructure.
3Reliability
If spin-coating is used for deposition, then thin films are formed, but significant material wastage occurs
Solution Approach 1:
Material is deposited only where needed in the form of precisely positioned droplets before any spreading or merging occurs. This preliminary localized deposition eliminates the need to coat entire substrate areas uniformly, reducing material usage to exactly what is required for the final film structure.
Solution Approach 2:
The deposited droplets self-spread and self-organize into contiguous films through capillary forces and surface tension without requiring additional material. The system uses the material's own physical properties to achieve uniform coverage from minimal initial deposition, eliminating waste associated with over-coating.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
PAINT achieves high precision in forming user-defined film profiles with nanometer scale accuracy, reducing material wastage and costs, while being agnostic to substrate type and topography, making it suitable for various applications including semiconductors and optics.
Implementation Method 1
dispensing drops of a pre-cursor liquid organic material at a plurality of locations on a substrate by an array of inkjet nozzles
Implementation Method 2
closing a gap between the substrate and a superstrate thereby allowing the drops to form a contiguous film
Implementation Method 3
irradiating the contiguous film with UV light to cure it
Data Source
AI summary
An inkjet-based process for programmable deposition of thin films of a user-defined profile. Drops of a pre-cursor liquid organic material are dispensed at various locations on a substrate by a multi-jet. A superstrate is held in a roll-to-roll configuration such that a first contact of the drops is made by a front side of the superstrate thereby initiating a liquid front that spreads outward merging with the drops to form a contiguous film captured between the substrate and the superstrate. A non-equilibrium transient state of the superstrate, the contiguous film and the substrate then occurs after a duration of time. The contiguous film is then cured to crosslink it into a polymer. The superstrate is then separated from the polymer thereby leaving a polymer film on the substrate. In such a manner, non-uniform films can be formed without significant material wastage in an inexpensive manner.